I need a FULL list of something...

[Gtafanboy]

Can someone list all the new things in the VI expansion pack before I buy it. I mean EVERYTHING. I have to go to school soon so I won't be back for a while(hehe not that it matters).

[lugh]

But we haven’t forgotten the main Medieval: Total WarTM game. The expansion pack also includes:

Three new playable factions - the Aragonese, the Sicilians and the Hungarians.
New units for many factions, including elite Arabic Faris cavalrymen, Russian Druhzina Cavalry, Hungary Jobbagy Infantry, and the fearsome, amazing Organ Gun - a Medieval “machine gun” of sorts!
A new pre-battle system that allows you to scout out enemy forces and organise your reinforcements before a battle.
Boiling oil in sieges! Beware of sending your men to attack the castle gates! http://www.totalwar.com/community/images/raider.jpg
Tweaks, changes and improvements to gameplay, including a couple of new buildings on the technology tree!
A brand new Viking Era campaign with a completely new map of the British Isles and Scandinavia.
8 new Viking Era factions, including the Saxons, Welsh, Mercians, Northumbrians, Scots, Picts, Irish - and not forgetting the Vikings!
A new Viking Era technology tree - including Drinking Halls, Sacrificial Shrines, a Warrior Hold and a few surprises.
New Viking Era military forces, including Huscarles, Saxon Fyrdmen, Viking Thralls, extremely scary and shield-bitingly fearsome Berserkers - and more! That's from the website. I'd need to be on my own pc to give a better list.
Hmm, the main advantage to upgrading to VI is that you get to play the various mods created as the vast majority are for 2.01. Some that I've tried are MTW XL, BKBs Supermod, Napoleonic TW, and Hellenic TW. They're all quite enjoyable if you ever get bored with the release version.

[Gtafanboy]

Do the new Mediaval Factions have units that they only have? Because I could make them playable in 1.1.

[Mouzafphaerre]

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Consider VI as MTW x 2...or at least 3/2. Apart from the additional campaign, the enhancements and moddability options are unmatchable. In many ways, VI is more moddable even than RTW + BI. Do get it; it's cheap nowadays and worth every Florin. ~;)
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[Mount Suribachi]

No excuse not to get it, its so cheap now. As well as the new campaign, extra units blah blah, attrition in sieges is higher (good), info managment is slightly improved, and, best of all, if you have multiple battles in one turn, you can save between battles. For me, it was worth buying for that feature alone.

[Ludens]

Do the new Mediaval Factions have units that they only have? Because I could make them playable in 1.1.
No. The Aragonese have the same line-up as the Spanish (both get Spanish Javelineers), the Sicilians are a standard Catholic faction with Italian/Byzantine ships. The Hungarians do have two unique units: Jobaggy (cheap but weak javelineers) and Szekely (excellent horse archer unit: fast and better-than-average melee stats).

[Mouzafphaerre]

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If you're into mods, the Modlet initiated by yours truly rearranges unit availability among a few other things. (The unfinished beta will be released -hopefully- shortly.)
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[elbasto]

In my opinion several tweaks to the campaign makes management easier to handle and that's the part of the game that I personally enjoy the most.

[ezoons]

With VI, I can now quick-save before battle (once the army match-up screen pops up). I'm not a fan of save/load-ing but sometimes I have to fight several battles in one turn and just don't have time for all of them

[Kekvit Irae]

The VI campaign is a refreshing change from the vanilla MTW campaign. No pope to annoy you, plenty of border disputes, and a faction (Vikings) that wont go away and cant be conquered (by normal means).